Inliners International Forums General Discussion Electrical Headlight Switch 6V

The 6V headlight switch on my '50 3100 will no longer light my dash lights.Anybody know how to check for an open circiut on the rheostat portion of the switch? I can't see a break in the winding just by eyeballing.Do I check the voltage from the side post and just ground it or do I actually ground it off the winding.I have
completely rewired the truck and the switch did work. And...
since a stock replacement is around $60, what's an alternative switch that will work if I need a new one. Thanks for any help.

DEar Drew;

Does the doam light come on when you turn the knob all the way CCW??

I think those are all in the same circuit along with the brake lights.

Some models have a tiny fuse in the switch for that.

Good luck.

Hey John,
The dome light works.It has a dedicated line source off the lightswitch with its own on/off at the light.The only fuses are the main ones on the firewall in the engine bay so I'm guessing the rheostat is bad somehow.

D;

Perhaps, but be sure. See if one side is 'hot' but not the other.

See if brake lights work.

Try TV tuner spray if one side is hot.

Patrick's may have the switch, or you have to get from one of thrck suppliers.

Good luck.

Good Morning guys!Well it turns out you are both right about a fuse in the switch.Over my morning coffee I read my shop and owners manual(again) and found small references about a 30 amp fusible link in the switch.No illustration though,so I don't know if I'd recognize it while looking at it.Anyway,if that fuse opened wouldn't that kill the entire switch and nothing would work?I have the switch out and the head and tail lights work.I was told to connect the dash light feed to the tail light contact and the bulbs do light with the switch on,however, I may also inadvertantly messed up the gounding of the bulb sockets becasue when I restored the dash instruments I painted the casings and may need to remove some paint around the socket holes to get a solid ground.As you can tell I'm not good at electrics when problems arise.I was amazed after rewiring that the truck started.LOL.
Oh,yeah,I'm headed to Radio Shack for the contact spray too.

D;

The head/tail fuse is in the form of a contct spring unit which opens if there's a 'short' in those circuits. If this occurs, the head/tail lights will go on/off till turned off or repaired.

The dash lights are separate, but they will 'flash' to as the spring/breaker kills all power to the switch.

You may be okay except for the paint. To check run a 'jumper' to one & see.

Have fun.

Walt, I removed the switch and took it with me to our local Radio Shack to ask them about looking at the winding and to buy some TV Tuner spray. A really nice employee put the switch in an ultrasonic(think that's right) bath they use for customer work and cleaned it up to looking nearly new.She checked the dimmer winding with ameter and it does have a break in it,although no employee could see it.Long story short,as suggested to me, I've attached the dash light feed to the tail light side and they work when the the switch is pulled on.They just stay bright.Regarding your suggestion about a wire shunt: Is that safe, no spark,no wire fire,
just inserting the wire that way?

Make sure the back side of the dash is Clean free of paint(Bare metal). The switch has to be grounded to metal for the dash lights to work.The little coil you are cleaning is actually on the ground side.The coil dims the dash lights by increasing or decreasing the resistance to ground not the power to the dash lights.

Drew,
If you don't need to adjust the dash lights, you can leave them hooked up to the tail light circuit. If this makes them too bright, you might try to hook up a ballast resistor between the tail light circuit and the dash lights. This will dim them some. If either of these is satisfactory, you don't need to repair/replace the switch.

regards,
Leon

Yeah, took us a week to figure out that some repro switches are made for 12V. If you run them on 6V the bi-metal spring gets hot in a view minutes and makes blingking headlights.

Frank

Drew,
Hook your dash lights to the tail light circuit, then go back to radio shack and ask for a variable resistor with a shaft that you can install a knob on. Insert it into the dash light wire and mount it out of site then you can adjust brightness as needed. An inexpensive fix. Some guys mount it in bottom lip of dash and most people don't notice it You probably don't need a knob if the shaft is long enough to grip with your fingers. If you happen to have an old variable speed heater switch laying around they can be used as a dimmer for your dash lights also.

Dear Drew;

Use a headlight switch for a 55-59. There the same (basic) thing and 12V. Your (push-pull) control will fit too.

Just take your time & 1 wire @ a time.

Good luck.